U.S. Pat. No. 7,566,216 (Kmoch et al.) purports to disclose an injection molding machine including a nozzle assembly having a channel for conveying a fluid. At least one cavity insert is removably mounted within a cavity plate. The at least one cavity insert defines a mold cavity, and a first portion of a gate for communicating the fluid between the nozzle assembly and the mold cavity. A gate insert defines a receptacle for the nozzle assembly, and further defines a second portion of the gate. The gate insert is floatably retained between the nozzle assembly and the at least one cavity insert. Preferably, the gate insert is retained by a gate insert plate that is disposed between the cavity plate and the nozzle assembly.
U.S. Pat. No. 5,254,305 (Fernandez et al.) purports to disclose a nozzle for injecting a moldable material that has a nozzle body which defines a nozzle channel leading to the nozzle outlet. The nozzle outlet is controlled by an axially slidable nozzle pin extending coaxially through the nozzle channel. A guide sleeve slidably supports the nozzle pin until it reaches the region adjacent the nozzle outlet. As a result, the length along which the nozzle pin is exposed to the moldable material is significantly reduced, thereby substantially eliminating the bending stresses applied to the nozzle pin by the pressure asymmetries in the incoming moldable material. The nozzle pin may also be retracted fully within the guide sleeve to provide an unobstructed path for the moldable material to flow through and consolidate as it approaches the nozzle outlet. With this arrangement, the incoming moldable material may be conveyed towards the nozzle channel asymmetrically with respect to the axis of the nozzle pin without any deleterious effect.
U.S. Pat. No. 6,398,542 (Romanski et al.) purports to disclose a valve gating apparatus for injection molding including at least one shutter disposed between the gate and the cavity melt channel into a mold cavity. The shutter is removably fastened to a rail member. When the rail member is moved laterally, the shutter moves between a closed position wherein flow of melt from the nozzle into the cavity is inhibited, and an open position wherein flow of melt into the cavity is unimpeded by the shutter.